MS3x losing sync only while cranking
 

Hi @ all

I'm losing sync while trying cranking with my MS3x and '99 1.8 Miata (euro spec)
Setup is still N/A, everything stock
Error codes are 31&32 (Miata 99-00 - 2 cams not seen & Miata 99-00 - 0 cams seen)

When I continue cranking for 20seconds or so, I'm often lucky and the engine fires up but thats not always the case. If it runs, it runs smoothly and doesn't lose sync at all anymore. I rev'd it up to 7000rpm and everything is working fine

I've already checked the Crank-Sensor gap and set it to 0,5mm - no change
Tried to adjust the pots inside the MS3 - no change (turned it while the engine was running untill it stalled, then turned it back slightly - didn't change a thing in the log or rpm reading)
Having the OEM ECU in the car, it fires right up, so sensors should be ok.

Please help!!

what is your skip events set to?

wow that was fast :)

"Skip Pulses" set to 3

which way did you turn?

i had set them them to WestfieldMX5's settings as I also followed his Assembly writeup
So everything full CCW, then R56 (lower one) back 10.5 turns and on MS3x R11 (top one) back 3.5 turns

Since I had sync loss while cranking with those settings, I tried to turn all of them back to full CCW and then one by one slowly CW untill the engine stalled and then backup'd slightly untill I got a rpm reading again
On the logs that didn't change a thing, but I just took a log at the end of turning them all, not while actually adjusting them.

Did I do that wrong? If yes, which pot should I adjust? Adjusting all of them doesn't seem right as I can never get correct settings for all of them at once...

edit:
I forgot to mention that when in Flood Clear Mode, I don't get any sync losses anymore!

no ideas?

I'm running out of ideas what to try next myself, so please help!

Can it be that cranking dwell or battery-dwell corrections is to high, so that the voltage drops to much or that the coils are backfiring or something?
I've got my settings from the DIY basemap for MS2 though...

Same problem
 

Did you ever get a resolution on this?
I still haven't gotten a good suggestion on where to set the pots on either the main board or the ms3x board. I'm assuming you either sold the car, gave up on the megasquirt, or figured out how to set the pots.
Any insight would be greatly appreciated even after all these years.
Thanks,
Steve

I solved the problem by setting the Ignition Input Capture to Falling Edge instead of Rising Edge. But thats only for MS3, as on MS2 its different and you need Rising Edge.
I didnt know that at first myself which is why I had those syncing problems.

After I had set it to Falling Edge, my pot settings didnt matter at all anymore and I just set them to the default "Westfield MX5" settings and it worked right away :cool: